Telephone Network Control
All telecommunication systems having multiple switching offices which require signaling between the offices. Telephone networks require signaling between switching offices for transmitting, routing and obtaining destination information, for transmitting alerting messages such as to indicate the arrival of an incoming call, and for transmitting supervisory information, e.g., relating to line status. Signaling between offices can use ‘in-band’ or ‘out-of-band’ transport.
In-band signaling utilizes the same channel that carries the communications of the parties. In a voice telephone system, for example, one of the common forms of in-band signaling between offices utilizes multi-frequency signaling over voice trunk circuits. The same voice trunk circuits also carry the actual voice traffic between switching offices. In-band signaling, however, tends to be relatively slow and ties up full voice channels during the signaling operations. In telephone call processing, a substantial percentage of all calls go unanswered because the destination station is busy. For in-band signaling, the trunk to the end office switching system serving the destination is set-up and maintained for the duration of signaling until the office informs the originating office of the busy line condition. As shown by this example, in-band signaling greatly increases congestion on the traffic channels, that is to say, the voice channels in the voice telephone network example. In-band signaling also is highly susceptible to fraud because hackers have developed devices which mimic in-band signals.
Out-of-band signaling evolved to mitigate the problems of in-band signaling. Out-of-band signaling utilizes separate channels, and in many cases separate switching elements. As such, out-of-band signaling reduces congestion on the channels carrying the actual communications traffic. Also, messages from the end user always utilize an in-band format and remain in-band, making it virtually impossible for an end-user to simulate signal messages which ride on an out-of-band channel or network. Out-of-band signaling utilizes its own signal formats and protocols and is not constrained by protocols and formats utilized for the actual communication, therefore out-of-band signaling typically is considerably faster then in-band signaling.
Out of band signaling networks typically include data links and one or more packet switching systems. Out-of-band signaling for telephone networks is often referred to as Common Channel Signaling (CCS) or Common Channel Interoffice Signaling (CCIS). In the U.S., most such signaling communication for telephone networks utilize Signaling System 7 (SS7) protocol. An SS7 compliant CCIS network comprises data switching systems designated Signal Transfer Point (STP) and data links between the STP and various telephone switching offices of the network, i.e., the Service Switching Points (SSPs). In intelligent versions of the telephone network including high level central database and control nodes, identified as Service Control Points (SCPs) such as an Integrated Services Control Points (ISCPs) by Telcordia Technologies, the CCIS network also includes data links connecting the high level control nodes to one or more of the STP.
The STP are program controlled packet data switching systems. In operation, an STP receives a packet data message from another node of the network, for example from an end office SSP. The STP analyzes point code information in the packet and routes the packet according to a static translation table stored with the STP. Any packet having a particular point code is output on a port going to the next CCIS signaling node specified by translation of that point code.
The development of the CCIS network has recently permitted the offering of a number of new service features provided by centralized program control from a high level control point. Such an enhanced telephone network is often termed an Advanced Intelligent Network (AIN). In an AIN type system, local and/or toll offices of the public telephone network detect one of a number of call processing events identified as AIN “triggers”. For ordinary telephone service calls, there would be no event to trigger AIN processing; and the local and toll office switches would function normally and process such calls without referring to the central database for instructions. An office which detects a trigger will suspend call processing, compile a call data message and forward that message via the CCIS signaling network to an ISCP which may include a Multi-Services Application Platform (MSAP) database. If needed, the ISCP can instruct the central office to obtain and forward additional information. Once sufficient information about the call has reached the SCP, the SCP accesses it's stored data tables in the MSAP database to translate the received message data into a call control message and returns the call control message to the office of the network via CCIS link. The network offices then use the call control message to complete the particular call. An AIN type network for providing an Area Wide Centrex Service was disclosed and described in detail and commonly assigned U.S. Pat. No. 5,247,571 to Key et al., the disclosure of which is incorporated herein in its entirety by reference. Existing AIN type systems, such as disclosed in the Key et. al. patent, utilize the routing functionality of the STP and the CCIS network as described above. Every time a specified switching office launches a query for an identified SCP, the translation table in the STP(s) of the CCIS network causes the STP(s) to route the query message to that ISCP.
Many of the enhanced communications services offered by the AIN permit a subscriber to input control information, to manage services as desired. For example, in a simple forwarding or redirection service, the subscriber might change the ‘forward to’ number from time to time to route calls to different destination. As another example, a subscriber might want to block calls unless they are to, or from, numbers on a list, and the subscriber would want to change the list of numbers from time to time. Some subscribers need to change certain information quite frequently, even for relative simple AIN services. Another example of an AIN feature is call waiting. Call Waiting, although it could be, is not an AIN service in Verizon. Call waiting is a telephone feature which alerts a called party to an incoming call when that party's telephone is busy with another call. An incoming call can be indicated to the called party by a click on the telephone line. At that point, the called party may place the existing call on hold and answer the new incoming call.
The Internet And Telephone Access
Many users today connect their computer terminals to the Internet over a conventional POTS telephone line through a Local Exchange Carrier (LEC) to an Internet Access Provider (IAP), which provides access to the Internet and Internet Service Providers (ISPs). Most users today have a single telephone line to their homes and must disable call waiting when they are connected to the Internet. When call waiting is disconnected, callers receive a busy signal as long as the called party is connected to the Internet. With the call waiting disabled, the called party is unaware of the incoming call and does not have the opportunity to either end their Internet session or place their Internet session on hold to answer the incoming call.
U.S. Pat. No. 5,982,774 details a system, which when a user is connected to the Internet over their telephone line through an Internet Access Provider (IAP), allows the user to place their Internet connection on hold and connect to the incoming call. The Local Exchange Carrier (LEC) sends a signal to the IAP that indicates the presence of the waiting call. The IAP then transmits this information to the user's terminal, and the user may take the call.
U.S. Pat. No. 5,805,587 discusses a method in which a facility is provided to alert a subscriber connected to the Internet of a waiting call via their Internet connection. The waiting call may be forwarded via the Public Switched Network (PSN) to a services' platform which establishes a connection to the subscriber via the Internet. The subscriber is then notified of the waiting call and allowed access to, if desired, the incoming call.
However, these systems are relatively inflexible and involve rerouting calls to an intelligent platform to provide the logic and call processing functionality of the services.
A need exists which will notify the called party who is engaged in an Internet session, of the incoming call and allow them to end their Internet session and receive the incoming call, without the overhead associated with other methods.